A wide variety of technical applications require sensors located at different locations. Often, the sensors use optical fibers to transmit information to a processing entity. When the number of sensors is large, their exact location sometimes becomes difficult to determine.
Traditionally, location and/or identification of sensors is done by attaching a visible tag to an optical fiber lead connecting to each individual sensor. This method of identification and/or location is prone to errors since tags may be mislabeled, may become detached from the optical fiber lead, and/or may be improperly referenced on a plan or map of the entire system layout. When one or more of these potential problems occurs in practice, it may be difficult to precisely locate and/or identify a specific sensor. This difficulty is compounded when sensors are part of a system that is routed through hard to reach locations such as conduits or walls.
Proposed solutions to impregnate embedded optical fibers with special materials that can be traced with sophisticated technology are costly and sometimes hard to implement and may even create health hazards. An example is described in U.S. Pat. No. 6,253,014 proposing an X-ray system for tracing optical fibers coated with a special coating that is opaque to X-ray radiation.
Against this background, it clearly appears that a need exists for more practical and less expensive solutions to obtain location information and/or identification information regarding sensors in optical paths such as optical fibers.